Driver alert system for the steering wheel of a motor vehicle

Abstract

A driver alert system for the steering wheel of a motor vehicle. The system comprises an electric motor, an eccentric mass connected to the electric motor, and a control circuit for providing electric supply to the electric motor in response to an alert activation signal The motor is controlled by the control circuit to an operation level of voltage during a portion of a vibration period with a non-vibration period following the vibration period, and the motor is over or under-controlled with respect to the operation range at the beginning or end of said vibration period.

1. A driver alert system for a steering wheel of a motor vehicle, comprising an electric motor, an eccentric mass connected to the electric motor and coupled with the steering wheel, a control circuit for providing electric supply to the electric motor in response to an alert activation signal, wherein the motor is controlled by the control circuit to an operation level of voltage during a portion of a vibration period with a non-vibration period following the vibration period, and the motor is over or under-controlled with respect to the operation level at the beginning or end of the vibration period. 
     
     
       2. A driver alert system according to  claim 1 , wherein the motor is at least 20% over-controlled with respect to the operation level. 
     
     
       3. A driver alert system according to  claim 2 , wherein the motor is at least 50% over-controlled with respect to the operation level. 
     
     
       4. A driver alert system according to  claim 1 , wherein the motor is under-controlled to a reverse current level at the end of the vibration period. 
     
     
       5. A driver alert system according to  claim 4 , wherein the absolute magnitude of the reverse current level is controlled to be approximately the same as the current level during the vibration period. 
     
     
       6. A driver alert system according to  claim 1 , wherein the operation level of voltage is essentially constant. 
     
     
       7. A driver alert system according to  claim 1 , wherein the control circuit is adapted to periodically interrupt the electric supply to the motor in order to create alternating of the vibration periods and the non-vibration periods. 
     
     
       8. A driver alert system according to  claim 7 , wherein all the vibration periods have approximately the same length of time. 
     
     
       9. A driver alert system according to  claim 7 , wherein all the non-vibration periods have approximately the same length of time. 
     
     
       10. A driver alert system according to any  claim 1 , wherein there is a plurality of the vibration periods and the vibration periods each have a length of time in the range of 250 ms to 5 s. 
     
     
       11. A driver alert system according to  claim 1 , wherein there is a plurality of the non-vibration periods and the non-vibration periods have a length of time in the range of 250 ms to 1 s. 
     
     
       12. A driver alert system according to  claim 1 , wherein the control circuit comprises a current maintaining path for the motor and circuitry for opening the current maintaining path at the end of the vibration period. 
     
     
       13. A driver alert system according to  claim 1 , wherein the electric motor is a DC motor. 
     
     
       14. A driver alert system according to  claim 1  wherein the operation voltage level is chosen to maintain a rotation frequency of the motor in the range of 30 to 70 Hz within the vibration period. 
     
     
       15. A driver alert system according to  claim 1 , wherein the electric motor is connected to a spoke of the steering wheel. 
     
     
       16. A driver alert system for a steering wheel of a motor vehicle, comprising an electric motor, an eccentric mass connected to an axis of the electric motor and coupled with the steering wheel, and a control circuit for providing electric supply to the electric meter in response to an alert activation signal, wherein the motor is controlled to provide one or more vibration periods in which the motor rotates the mass to produce vibrations, and one or more non-vibration periods in which the mass is not rotated with the one or more vibration periods alternating with the one or more non-vibration periods, and the motor is controlled during a vibration period after an initial segment of the vibration period at an operation voltage level, and the motor is over-controlled with respect to the operation level during the initial segment. 
     
     
       17. A driver alert system according to  claim 16 , wherein the motor is at least 20% over-controlled during the initial period with respect to the operation level. 
     
     
       18. A driver alert system according to  claim 16 , wherein the motor is at least 50% over-controlled during the initial period with respect to the operation level. 
     
     
       19. Driver alert system according to  claim 16 , wherein the motor is under-controlled with respect to the operation level to a reverse current level at an end segment of one or more of the vibration periods. 
     
     
       20. A driver alert system according to  claim 16 , wherein the operation level is essentially constant. 
     
     
       21. A driver alert system according to  claim 16 , wherein the control circuit is adapted to periodically interrupt the electric supply to the motor in order to create the non-vibration periods. 
     
     
       22. A driver alert system according to  claim 21 , wherein the vibration periods each have a length in the range of 250 ms to 5 s. 
     
     
       23. A driver alert system according to  claim 21 , wherein the non-vibration periods each have a length in the range of 250 ms to 1 s. 
     
     
       24. A driver alert system according to  claim 16 , wherein the operation voltage level is chosen to maintain a rotation frequency of the motor in the range of 30 to 70 Hz within the vibration period. 
     
     
       25. A driver alert system for a steering wheel of a motor vehicle, comprising an electric motor, an eccentric mass connected to an axis of the electric motor and coupled with the steering wheel, and a control circuit for providing electric supply to the electric motor in response to an alert activation signal, wherein the motor is controlled to provide one or more vibration periods in which the motor rotates the mass to produce vibrations and one or more non-vibration periods following a vibration period in which the mass is not rotated, and the motor is controlled during the vibration period before an end segment of the vibration period at an operation level, arid the motor is under-controlled with respect to the operation level during the end segment. 
     
     
       26. A driver alert, system according to  claim 25 , wherein the motor is under-controlled with respect to the operation level to a reverse current level at an end segment of the vibration period. 
     
     
       27. A driver alert system according to  claim 25 , wherein the operation level is essentially constant. 
     
     
       28. A driver alert system according to  claim 25 , wherein the control circuit is adapted to periodically interrupt the electric supply to the motor in order to alternate a plurality of the vibration periods and a plurality of the non-vibration periods. 
     
     
       29. A driver alert system according to  claim 25 , wherein the vibration periods have a length in the range of 250 ms to 5 s. 
     
     
       30. A driver alert system according to  claim 25 , wherein the non-vibration periods have a length in the range of 250 ms to 1 s. 
     
     
       31. A driver alert system according to  claim 25 , wherein the electric supply provides an operation level is chosen to maintain a rotation frequency of the motor in the range of 30 to 70 Hz within the vibration period.